I not sure either how galley space is related to this. Im not cabin crew, so I’m also happy to be corrected or educated. Surely 180 paper cups (stackable), a couple of boxes of tea bags/jars of coffee and a box of UHT milk sachets could only take up a shelf or two of a bar cart (and probably less space than the free crisps!)? I presume the planes potable water tanks can carry the necessary water unless they didn’t spec the planes for those. Maybe they cut back on water heating facilities but surely the pots or flasks on the trolleys are filled and then the water heaters can heat the next batch while that one is being served. Given that tea and coffee were previously served in thimble-sized cups it can’t take that much hot water!